That the earth goes around the sun is well-known to everybody.地球圍繞著太陽(yáng)轉(zhuǎn)是眾所周知的事實(shí)。（= It is well-known to everybody that the earth goes around the sun.）
謂語(yǔ)動(dòng)詞單數(shù)。
只能使用whether表示是否， if 不可以使用
用何連詞看從句中缺少什么成分來(lái)決定
表語(yǔ)從句
1. The problem is who we can get to replace her.
2. That is what he meant.
3. The question is how he did it.
4. That’s where he lives.
5. This was when I really got to know the United States.
6. Things are not always as they seem to be.
7. His first question was whether Tom had arrived yet.
8. The problem is that he does not come.